Interior and Exterior Angles of Polygons Practice - PDF

Summary

This document, created by Gina Wilson in 2014, is a collection of practice questions focusing on interior and exterior angles of polygons. It reviews key formulas such as the sum of interior angles and the exterior angle formula. The material covers various polygons, and includes practice problems.

Full Transcript

Okay, here is the converted text from the images into a structured markdown format. I have focused on retaining information, mathematical formulas, and table structures while aiming for clarity and readability. ### Page 1 Name: Class: Topic: Date: **Main Ideas/Questions | Notes** ------------ | -...

Okay, here is the converted text from the images into a structured markdown format. I have focused on retaining information, mathematical formulas, and table structures while aiming for clarity and readability. ### Page 1 Name: Class: Topic: Date: **Main Ideas/Questions | Notes** ------------ | ------------- **Interior Angles Sum** | The sum of the degrees in any polygon can be determined by the number of triangles that can be drawn within the polygon. Complete the table below and look for a pattern to find the sum of the degrees in any polgon. **Table of Interior Angles** | Polygon | Picture | # of Sides | # of Triangles | Sum of Interior Angles | | ------------- | ------------------------------------------- | ---------- | -------------- | ---------------------- | | Triangle | Triangle Image | 3 | 1 | 180° | | Quadrilateral | Quadrilateral Image | 4 | 2 | 360° | | Pentagon | Pentagon Image | 5 | 3 | 540° | | Hexagon | Hexagon Image | 6 | 4 | 720° | | Heptagon | Image marked with an "X" | 7 | 5 | 900° | | Octagon | Image marked with an "X" | 8 | 6 | 1080° | | Nonagon | Image marked with an "X" | 9 | 7 | 1260° | | Decagon | Image marked with an "X" | 10 | 8 | 1440° | **Sum of Interior Angles Formula!** | If n represents the number of sides of a polygon, then the sum of the interior angles (S) can be found using the formula: | $S= (n-2) \cdot 180$ **Interior Angle of a Regular Polygon** | A regular polygon is one is which all sides are equal; therefore all angles are equal! To find the measure of an interior angle in a regular polygon, use: | $\frac{S}{n}$ | (Sum of int $\angle$'s $\div$ # of sides) Gina Wilson (All Things Algebra), 2014 ### Page 2 **Interior Angles Practice!** 1. Find the sum of the interior angles of a 15 gon. $S = (15-2) \cdot 180 = 2340°$ 2. Find the sum of the interior angles of a 21-gon. $S = (21-2) \cdot 180 = 3420°$ 3. What is the measure of each interior angle of a regular pentagon? $S = (5 - 2) \cdot 180 = 540$ $540/5 = 108°$ 4. What is the measure of each interior angle of a regular 18-gon? $S = (18-2) \cdot 180 = 2880$ $2880/18 = 160°$ **Exterior Angles Sum** Exterior angles are always supplementary to their adjacent interior angle. On the polygons below, find the measure of each exterior angle along with the sum of all exterior angles. *Triangle:* Image of triangle with exterior and interior angles labeled, Sum of Exterior Angles: $360°$ *Quadrilateral:* Image of quadrilateral with exterior and interior angles labeled, Sum of Exterior Angles: $360°$ *Pentagon:* Image of pentagon with exterior and interior angles labeled, Sum of Exterior Angles: $360°$ *Hexagon:* Image of hexagon with exterior and interior angles labeled, Sum of Exterior Angles: $360°$ Conclusion: The sum of the exterior angle of any polygon is $360°$ **Exterior Angles Practice!** 5. What is the measure of each exterior angle of a regular hexagon? $\frac{360}{6} = 60°$ 6. What is the measure of each exterior angle of a regular 24-gon? $\frac{360}{24} = 15°$ 7. If the exterior angle of a regular polygon measures $12°$, how many sides does the polygon have? $\frac{360}{x} = 12$ $12x = 360$ $x = 30$ 8. If the exterior angle of a regular polygon measures $40°$, how many sides does the polygon have? $\frac{360}{x} = 40$ $40x = 360$ $x = 9$ Gina Wilson (All Things Algebra), 2014 ### Page 3 **PRACTICE: Interior & Exterior Angles of Polygons** **Formulas Review** | Formula | | ----------- | | Sum of Interior Angles of a Polygon: $S = (n-2) \cdot 180$ | | Interior Angle of a Regular Polygon: $\frac{S}{n}$ | | Sum of Exterior Angles of a Polygon: $360°$ | | Exterior Angle of a Regular Polygon: $\frac{360}{n}$ | | Number of Sides of a Regular Polygon: $\frac{360}{\text{ext } \angle}$ | **Practice Questions** 1. What is the sum of the measures of the interior angles of a pentagon? $S = (5-2) \cdot 180 = 540°$ 2. What is the sum of the measures of the interior angles of a 27-gon? $S = (27-2) \cdot 180 = 4500°$ 3. What is the measure of each interior angle of a regular octagon? $S = (8-2) \cdot 180 = 1080$ $1080/8 = 135°$ 4. What is the measure of *each* interior angle of a regular 20-gon? $S=(20-2) \cdot 180 = 3240$ $3240/20=162°$ 5. Five angles of a hexagon measure $119°$, $129°$, $104°$, $139°$, and $95°$. What is the measure of the sixth angle? $S = (6-2) \cdot 180 = 720°$ $720-586 = 134°$ 6. The sum of the interior angles of a polygon is $1620°$. How many sides does the polygon have? $1620 = (n-2) \cdot 180$ $9 = n-2$ $11 = n$ 7. The sum of the interior angles of a polygon is $3960°$. How many sides does the polygon have? $3960 = (n-2) \cdot 180$ $22 = n-2$ $24 = n$ 8. What is the sum of the measures of the exterior angles of a nonagon? $360°$ 9. What is the measure of each exterior angle of a 20-gon? $\frac{360}{20} = 18°$ Gina Wilson (All Things Algebra), 2014 ### Page 4 10. If the exterior angle of a regular polygon measures $9°$, how many sides does the polygon have? $\frac{360}{n} = 9$ $9n = 360$ $n = 40$ 11. If the interior angle of a regular polygon measures $108°$, how many sides does the polygon have? ext $\angle = 12$ $\frac{360}{n} = 72$ $72n=360$ $n = 5$ 12. Find the value of x. Image of a quadrilateral with angles labeled. $360-244=116°$ 13. Find the value of x. Image of a quadrilateral with angles labeled. $900-806 = 94°$ 14. Solve for x. Image of a polygon with angles labeled in terms of x $110 + 8x - 1 + 5x + 36 + 116 + 7x + 19 + 6x - 2 = 720$ $26x + 278 = 720$ $26x = 442$ $x = 17$ 15. Find m∠B. Image of a quadrilateral ABCD $8x+7 + 5x+18 + 10x+13 + 14x -11 = 360$ $37x + 27 = 360$ $37x = 333$ $x = 9$ $m\angle B = 8(9) + 7 = 79°$ 16. Solve for x. Image of a polygon with angles labeled $10(10x + 4) = 1440$ $100x + 40 = 1440$ $100x = 1400$ $x = 14$ 17. Solve for x. Image of a polygon with angles labeled in terms of x $5x + 4 + 4x + 9 + 9x -6 + 4x + 1 + 7x + 4 = 360$ $29x + 12 = 360$ $29x = 348$ $x = 12$ Gina Wilson (All Things Algebra), 2014 ### Page 5 Name: Class: Topic: Date: **Main Ideas/Questions | Notes** ------------ | ------------- **Properties of Parallelograms** | 1. Opposite sides are parallel. | | 2. Opposite sides are congruent. | | 3. Opposite angles are congruent. | | 4. Consecutive angles are supplementary. | | 5. Diagonals bisect each other. **Directions:** Each quadrilateral below is a parallelogram. Find the missing measures. 1. Image of parallelogram ABCD with AD=8, AB=15, DC=15 $AD = 8$ $DC = 15$ $m \angle A = 112°$ $m \angle B =68°$ $m \angle C = 112°$ 2. Image of parallelogram JKML with JK=21, KL=29 $JK = 21$ $KL = 29$ $m \angle J = 127°$ $m \angle K = 53°$ $m \angle M = 53°$ 3. Image of parallelogram RSTU with RT=30 $UT = 27$ $ST = 18$ $VS = 7$ $VT = 15$ 4. Image of parallelogram CDEF $m\angle DEC= 63°$ $m \angle CDE= 46°$ $m \angle ECD = 71°$ $m \angle FED= 134°$ $m \angle DFE= 25°$ 5. Given XY = 15, WX = 22, ZX = 52, WT = 23,$m \angle WZY= 72°$, $m \angle WXT = 35°$, and $m \angle ZWT = 59°$. Image of parallelogram WXYZ with diagonal XT $WZ= 15$ $ZY = 22$ $TX=26$ $WY=46$ $m \angle TZY= 35°$ $m\angle WZY= 72°$ $m \angle XYZ= 108°$ $m \angle XYT= 49°$ 6. Given $m \angle GHF= 34°$, $m\angle HJF = 124°$, and $m \angle FKJ = 79°$. Image of parallelogram FGJH with segment FK $m\angle FGJ= 56°$ $m\angle FGH= 124°$ $m\angle JGH= 67°$ $m\angle HFJ= 34°$ $m\angle FGJ= 61°$ $m\angle HKJ= 181°$ $m\angle FHJ= 22°$ $m\angle GJF= 67°$ Gina Wilson (All Things Algebra), 2014 ### Page 6 7. Solve for x. Image of Parallelogram $9x-25= 5x+7$ $4x = 32$ $x=8$ 8. Find YZ. Image of Parallelogram $19x-31= 11x+1$ $8x = 32$ $x\angle B = 4$ $YZ= 19(4)-31= 45$ 9. If TV = 74 and WV = $4x+1$, solve for x. Image of Parallelogram $2(4x +1)=74$ $8x+2=74$ $8x=72$ $x=9$ 10. if NS = $2x+7$ and SQ = $5x-23$, Find NQ. Image of Parallelogram $5x -23=2x+7$ $3x=30$ $x = 10$ $NS= 2(10)+7 = 27$ $NQ= 2(27)= 54$ 11. Find $m\angle B$ Image of Parallelogram $6x -15= 4x +11$ $2x = 26$ $x = 13$ $m\angle C = 4(13) +11 = 63$ $m\angle B = 180 - 63 = 117°$ 12. Find $m\angle R$ Image of Parallelogram $8x+3x+5=180$ $11x -7=180$ $11x \angle B = 187$ $x = 17$ $m\angle P = m\angle R$ $m\angle P = 3 (17) +5 = 56°$ 13. If $m\angle KLH = 134°$, Solve for x. Image of Parallelogram $4x =3$ $4x + 9 +25+134 =180$ $4x=12$ 14. If $m\angle ABC = 1115°$ ,find $m\angle ADB$. Image of Parallelogram $ \angle B = 6x -11+4x+6=115$ $ 10x-5=115$ $10x =3$ mLADB = 6 (12) - 11 = 61° Gina Wilson (All Things Algebra), 2014 ### Page 7 **Proving Parallelograms in the Coordinate Plane** | Method | Description | Instructions | | ------ | ------ | ------ | | Method 1 | Prove both pairs of opposite sides are congruent. | If $\overline{AB} \cong \overline{CD}$ and $\overline{DA} \cong \overline{BC}$, then ABCD is a parallelogram. Use the distance formula.| | Method 2 | Prove both pairs of opposite sides are parallel.| If $\overline{AB} \parallel \overline{CD}$ and $\overline{AD} \parallel\overline{CB}$, then ABCD is a parallelogram. Use slope formula. | | Method 3 | Prove one pair of opposite sides are congruent and parallel. | If $\overline{AB} \cong \overline{CD}$ and $\overline{AB} \parallel \overline{CD}$, then ABCD is a parallelogram. Use the distance + slope formulas | Directions: Determine whether the figure is a parallelogram using the distance formula. 1. $A(−7, 4), B(1, 2), C(9, −8), D(1, −6)$\ $AB=\sqrt{(1+7)^{2}+(2-4)^{2}}=\sqrt{64+4}=\sqrt{68}$ $BC=\sqrt{(9-1)^{2}+(-8-2)^{2}}=\sqrt{64+100}=\sqrt{164}$ $CD=\sqrt{(1-9)^{2}+(-6+8)^{2}}=\sqrt{64+4} = \sqrt{68}$ $DA=\sqrt{(1+7)^{2}+(-6-4)^{2}}=\sqrt{64 + =100} = \sqrt{164}$ YES! ABCD is a Parrallelogram 2. $P(−4, 2), Q(6, 4), R(11, −2), S(2, −3)$\ $PQ=\sqrt{(6+4)^{2}+(4-2)^{2}}=\sqrt{100+4}=√104$\ $RS=\sqrt{(2-11)^{2}+(-3+2)^{2}}=\sqrt{81+1}=√82$\ $\overline{PQ} \ncong \overline{RS}$ No! PQRS is not a Parallelogram Gina Wilson (All Things Algebra), 2014 ### Page 8 Directions: Determine whether the figure is a parallelogram using the slope formula. 3. W(−7, −4), X(1, −6), Y(5, −13), Z(−12) $m\overline{WX} = \frac{-6 + 4}{1 + 7} = \frac{-2}{8}=-\frac{1}{4}$ $m\overline{XY} = \frac{-13 + 6}{5 - 1} = \frac{-7}{4}$ $m\overline{WZ} = \frac{-12 + 4}{1 + 7} = \frac{-8}{8}= -1$ NO! WXYZ is not a parallelogram. 4. E(0, 8), F(6, 10), G(2, 0), H(−4, −2) $m\overline{EF} = \frac{10 - 8}{6-0}=\frac{2}{6} =\frac{1}{3}$ $m\overline{GH} = \frac{-2 - 0}{- 4 - 2} = \frac{-2}{- 6} = \frac{1}{3}$ $m\overline{FG} = \frac{0 - 10}{2- 6} = \frac{-10}{- 4} = \frac{ 5}{2}$ $m\overline{EH} = \frac{-2 - 8}{- 4 - 0} = \frac{-10}{- 4} = \frac{ 5}{2}$ YES! EFGH is a parrallelogram Directions: Determine whether the figure is a parallelogram using the distance and slope formulas 5. J(−9, −2), K(−5, 1), L(1, −4), M(−3, −7) $JK=\sqrt{(-5+ 9)^{2}+(1 + 2)^{2}} = \sqrt{16 + 9} = \sqrt{25}= 5$ $LM=\sqrt{(-1+ 3)^{2}+(-1+ 7)^{2}} = \sqrt{16 + 9} = \sqrt{25} = 5$ $m\overline{JK} = \frac{1 + 2}{- 6 + 9}= \frac{3}{4}$ $m\overline{LM} = \frac{5 + 4}{- 3 - 1} = \frac { 5}{4}$ YES! JKLM is a parallelogram 6. S(1, 5), T(10, 7), U(14, 1), V(5, −1) $ST = \sqrt{(10 - 1)^{2}+(7 - 5)^{2}} = \sqrt{81 + 4} = √(\frac{85}$ $UV = \sqrt{(5 - 11)^{2}+(-1 - 1)^{2}} = \sqrt{149 + 4} = {√\frac{33}{}}$ No! STUV is not a parallelogram GIna Wilson (All Things Algebra), 2014